Damp Protection Arrangement and Method of Protecting a Space Against Damp

ABSTRACT

A damp protection arrangement for a space confined by floor, ceiling and wall portions in a building and comprising the following components: a damp permeable first layer structure ( 80 ), inside the space comprising at least one wall portion ( 16/80 ) of said portions; a second layer structure ( 60 ), inside the space covering at least the first layer structure ( 60/80 ); a continuous air gap ( 50 ), separated from the space and defined between the first and the second layer structures; an air inlet at a lower level in the space and communicating with the air gap ( 50 ); an air outlet at a higher level in the space and communicating with the air gap; and heating source ( 54 ) inside the air gap ( 50 ) for providing an air flow in the air gap between the inlet and the outlet and capable of dehumidifying layer structures.

TECHNICAL FIELD

The invention relates to a damp protection arrangement for a space confined by floor, roof and wall portions in a building. The invention also relates to a method of protecting such a space from damp.

BACKGROUND

The problems related to damage from damp are serious when, as is common in Nordic countries, the houses are constructed with hollow spaces in floor structures and walls. Mildew damage as well as chemical emissions arise if water enters these hollow spaces. This problem grew when the houses were made tight in the beginning of the seventies. Thereby also the natural ventilation that occurs in floor structures and walls was also removed.

In Sweden alone the cost for damp damage is equivalent to about a half billion

A smaller part of this cost includes the cost of repairing leakage such as fractured pipes etc. The main part of this cost is in the work in connection with tearing up, drying and reconstructing the spaces, for example bathrooms, that are subjected to water damage. This is in spite of the leak possibly being located at a quite different place than the bathroom. Currently a problem is also that many rather newly installed bathrooms have to be teared up and dried out solely of the reason that the impermeable layers of an upstair neighbor are leaking.

The insights forming the basis of the invention may be expressed as follows:

-   -   If a water damage were observed on an early stage, large costs         would be saved.     -   If the damp could be dried out without having to tear away walls         and floor structures, still more costs would be saved.     -   If the damp within the walls could be ventilated away in a         controllable manner, emissions causing illness would also be         ventilated away, and the number of bad houses would decrease.     -   If the necessary measures resulted in cost savings they would be         employed.     -   If the necessary measures did not use up space, they would also         be used.     -   If the necessary measures were simple, the craftsmen would adopt         them.     -   If the necessary measures can be applied within current         regulations, there are no formal obstacles to apply them.

PRIOR ART

It is known from SE 9701542-4 C2 to install board elements mounted spaced from walls and floor for the purpose of ventilating a room, so that between the walls and the floor a ventilation space is formed for a through flow of air. This technology is used in order to ventilating away detrimental concentrations of damp and gases, such as radon gas, in a preventive purpose.

For wet spaces such as bathrooms and the like, it is known from SE 8203579-1 B to ventilate a damp sub floor by an impermeable, damp proof board at a space from the floor, which board extends upwards along and also at a distance from a lower portion of an adjacent wall.

DISCLOSURE OF THE INVENTION

An object of the invention is to further develop the prior art and provide a low-cost, simple and space-saving solution to the problems of damp, particularly but not exclusively in wet spaces.

In accordance with an aspect of the invention, the damp protection arrangement comprises the following features in combination:

-   -   A damp permeable first layer structure inside the space         comprising at least one wall portion of said portions.

Thereby, portions lying behind such as insulation in the building may be defined and be provided a well defined flow-promoting smooth face of an air gap capable of conveying damp mixed up with possibly harmful substances.

-   -   A second layer structure, inside the space covering at least the         first layer structure.

Thereby also a smooth face may be defined, i.e. the opposite face of the air gap. The second layer structure may be optionally permeable to damp for being suitable in a wet space, or permeable to damp for being suitable for other types of spaces that run the risk of being subjected to damp damages.

-   -   A continuous air gap, separated from the space defined between         the first and the second layer structure.

Thereby an insulated passage is provided for accumulation and exposure of damp, for interaction with an air flow and for transport of resulting damp air in the space.

-   -   An air inlet at a lower level in the space and communicating         with the air gap.

Thereby a passage may be provided for transport of dry air to the air gap.

-   -   An air outlet at a higher level in the space and communicating         with the air gap.

Thereby a passage may be provided for transport of the damp air out of the space.

-   -   A heating source inside the air gap for providing an air flow in         the air gap between the inlet and the outlet and capable of         dehumidifying the layer structures.

By the heating source being located inside the air gap, the heating source can directly heat the dry air, so that the dry air will have a high tendency to attract the damp or humidity, possibly mixed up with harmful substances, and bring the resulting humid air into motion upwards to the outlet and out of the building.

Other features and advantages of the present invention are apparent from the claims and the following detailed description of exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagrammatic sectional cutaway view of a building having a space provided with a damp protection arrangement according to the invention;

FIG. 2 is a detail view in larger scale of a first encircled area of FIG. 1;

FIG. 3 is a detail view in larger scale of a second encircled area of FIG. 1; and

FIG. 4 is a detail view in larger scale of a third encircled area of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS

Generally referenced by 10 in FIG. 1 is a portion of a building having a floor portion 12, a ceiling portion 14 and wall portion 16 defining a wet space 24. While the damp protection arrangement in the exemplary embodiment is described in connection with a wet space, and primarily may be applied to wet spaces, the damp protection arrangement according to the invention, as the invention is defined in the claims, may also be applied to other spaces that run the risk of being subjected to damp damages, for example spaces directly below a leaking roof. For the access to the wet space, also shown is a door 26.

The floor, ceiling and wall portions 12, 14, 16 may be of varying construction. While the invention may be applied on pure concrete structures, it is primarily intended for portions, for example infill portions having battens and beams (not shown) defining hollow spaces that in turn may be filled with heat insulating materials 20 and 22 respectively. Such portions are particularly sensitive to damp damages.

According to the invention, inside the wet space 24 confined by the floor, ceiling and wall portions 12, 14, 16, a damp protection arrangement is provided, comprising a damp permeable layer structure 70, 80 and a damp impermeable layer structure 40, 60 that define a continuous air gap 50 therebetween. It is to be noted that FIG. 1 shows the damp protecting arrangement only in illustrative purpose, showing excessive thicknesses and spacings between the layer structures. A damp protection arrangement according to the invention needs no more space than a conventional original layer construction in a wet space. In principle only the thin air gap and the thin damp permeable layer 80 are added in the wall portions 16, while in the floor portion 12 only the air gap is added; in conventional wet space walls often double layers of gypsum wall board is used, were the added gypsum layer is about as thick as the air gap. Doubled gypsum wall board layers are, however, unsuitable together with the present invention, as the resulting doubled paper layers between the boards suck up water and acts as obstructing to the dehumidification.

While the layer structures in the embodiment shown are indicated as stretching over all floor and wall portions, 12, 16, they may be used to a varying extent in many combinations depending on varying constructions of the floor and wall portions in the particular case. In an extreme case, for example comprising a concrete building structure having only one differing wall portion that is especially sensitive to damp damage, it may be sufficient to use the layers structures 60, 80 only at the corresponding wall face in the wet space (not shown). In the normal case, however, the layer structures extend also over the floor portion 12 of the wet space 24 and over all wall portions. Directly to the ceiling portion 14 there should not be any layer structure at all as that structure then would run the risk of keeping damp in the corresponding concrete structure or in the insulating material 20. In the example shown, a damp permeable ceiling layer 90 needs to be spaced from the ceiling portion 14 to keep the continuous air gap 50 separated or insulated from the damp protected wet space 24.

As is more clearly apparent from FIG. 2, the damp permeable layer structure 80 adjacent to a wall portion 16, comprises a damp permeable layer 82. The outer face of the damp permeable layer 82 serves to form a preferably flat face of the air gap 50 and to keep possible insulations 22 in place in the wall portion 16 lying behind. It is however, within the scope of the appended claims also conceivable that the damp permeable layer structure is composed of the present wall portion only, with or without insulation and without any supplementary layer. The damp permeable layer 82 is however in the embodiment shown preferably a cloth of geotextile or a board of cement; also other materials may however be suitable.

The layer structures 16 adjacent to the wall portion 16 comprises from the inside and out to the wet space 24 a supporting layer 66, a damp impermeable layer 64 and a surface layer 62. The support layer 66, the inner face of which serves to form the opposite flat face of the air gap 50 and the outer face of which accordingly carries the impermeable layer 64 and the surface layer 62, is a board of wet room gypsum in the exemplary embodiment but can also consist of other supporting board materials. The impermeable layer 64 is a water tight moisture barrier of a known type applied to the outer surface of the support layer 66. On the impermeable layer 64 the surface layer is finally applied in a conventional manner, in the exemplary embodiment a layer of tiles together with fastening and joining compounds.

As is more clearly apparent from FIG. 3, the damp permeable layer structure 70 adjoining a floor portion 12, comprises a damp permeable layer 72. The top face of the damp permeable layer 72 serves to form a flat face of the air gap 50 and to keep possible insulation 20 in place in the underlying floor portion 12. In the exemplary embodiment, the damp permeable layer 72 is a conventional—in case of a reconstruction possibly already present—sub floor layer, for example made of floor boards based on wood fibers, but also other materials may be suitable. In order to increase the damp permeability in relatively impermeably sub floor layers, ventilating bores 74 may be drilled by using a suitable bore diameter and distribution over the floor surface, as indicated by 15 lines in FIG. 3. The bores 74 may be covered by a vapour permeable but water impermeable cloth 76.

The layer structure 40 adjoining the floor portion 12, in the exemplary embodiment comprises from the inside and out to the wet space 24, a support layer 48, a layer 46 providing floor inclination, an impermeable layer 44 and a surface layer 42. The support layer 48 the inside of which serves the purpose of forming the opposite flat side of the air gap 50 and the outside of which accordingly supports the remaining layers 46, 44, 42, in the exemplary embodiment for example a conventional damp resistant floor board of a gypsum type, but may also consist of other supporting board materials. The layer 46 that provides the inclination to the floor is a filling compound 46 of a known type. The impermeable layer 44 is a moisture barrier of a known type applied on the top surface of the layer 46. On the impermeable layer 44 is finally applied the surface layer 62 in a conventional manner, in the exemplary embodiment a clinker layer together with fastening and joining compound.

The gap width of the air gap 50 that typically can be about 1 cm, is maintained between adjoining layer structures 40, 70 and 60, 80 respectively, by spacers 52 such as elongated strips or spars of wood material. Other types of spacers may however also be usable. As is indicated in FIG. 3 by the broken spacer 52 in the air gap 50, the spacers at the floor portion 12 may be arranged by interspaces in the longitudinal as well as in the transverse direction in the floor plane in order that the air flow from the air gap 50 at the floor portion 12 may be distributed to mutually perpendicular air gaps 50 at the wall portion 16.

To heat the air in the air gap 50 and to increase the air flow that is indicated by filled arrows on the drawing, in the embodiment shown there is provided a heating cable 54 (2) at a low level inside the portion of air gap 50 that extends along the wall portions 16. The heating cable 54 is in a suitable manner, for example by cable clamps 56, attached to the outside of the damp permeable layer 80, and runs horizontally across the air flow along the entire air gap 50. As is indicated in FIG. 1, the heating cable is connected to the electric network (not shown) of the building 10 through an electric cable 100. An electronic unit 102 may in a manner known per se be provided with a switch for switching the heating power on and off, and possibly also be provided with equipment capable of controlling the heating power.

As is further indicated in FIG. 1, the damp protection arrangement can also be adapted to monitor the state of the air gap 50 and be brought into function by itself: In the air gap 50 is a sensor 104 adapted to sense the presence of damp or moisture in the air gap 50 and to signal the result through a signal line 106 to the electronic unit 102 so that the unit 102 is capable of turning on and off and/or controlling the heating power in response to the signals from the sensor 104.

While the inlet for dry air to the air gap 50 may be arranged in other ways at a low level in the wet space 24, in the embodiment according to FIG. 4 an air inlet 30 extends to the air gap 50 in the level of the air gap 50 through a threshold 28 at the door 26 to the wet space 24. The air inlet 30 can consist of a plurality of transverse openings or an elongated gap or slot in the threshold 28 and have an inlet filter (not shown) preventing inlet of dust or the like.

In the embodiment shown in FIG. 1, the outlet for air from air gap 50 comprises a piece 92 of tubing extending from the inside of the wet space 24 through the ceiling layer 90 to an exhausted passage 96 in the building 10. The portion of the piece 92 of tubing that is insulated from the wet space 24 by the ceiling layer 90 is provided with perforations 94 through which the air from air gap 50 can be sucked out to the exhausted passage 96 and out of the building 10.

Pipes for water and sewer to the wet space 24 are insulated in the passage through the air gap 50 in a suitable manner, for example by sleeves of expanded plastics material (not shown). 

1. A damp protection arrangement for a space confined by floor, roof and wall portions (12, 14, 16) in a building, characterised by a damp permeable first layer structure (70, 16/80), inside the space (50) comprising at least one wall portion (16) of said portions; a second layer structure (40, 60), inside the space covering at least the first layer structure (70, 16/80); a continuous air gap (50), separated from the space and defined between the first and the second layer structures an air inlet (30) at a lower level in the space (24) and communicating with the air gap (50); an air outlet (94) at a higher level in the space (24) and communicating with the air gap (50); and a heating source comprising a heating cable inside a portion of the air gap (50) parallel to a wall portion (16) of said portions the air gap (50) for providing an airflow in the air gap between the inlet (30) and the outlet (94) and capable of dehumidifying the layer structures.
 2. The damp protection arrangement according to claim 1, wherein the heating cable (54) extends generally horizontally inside the air gap (50).
 3. The damp protection arrangement according to claim 1, wherein the first and second layer structure also covers a floor portion (12) of said portions.
 4. The damp protection arrangement according to claim 1, wherein the first layer structure (80) comprises a geo textile cloth (82).
 5. The damp protection arrangement according to claim 1, wherein a damp permeable inner ceiling layer (90) covers a ceiling portion (14) of said portions via an interspace, said interspace communicating with the air gap (50).
 6. The damp protection arrangement according to claim 5, wherein the air outlet (94) is provided in said interspace.
 7. The damp protection arrangement according to claim 6, wherein the air outlet comprises perforations (94) in a piece of tubing (92) for exhaust air from said space (24) and extending through the interspace.
 8. The damp protection arrangement according to claim 1, wherein the air inlet (30) is in communication with an adjoining room in the building (10).
 9. The damp protection arrangement according to claim 8, wherein the air inlet (30) extends through a door threshold (28) into communication with the air gap (50).
 10. A method of protecting a space (24) from damp, said space being confined by floor, roof and wall portions (12, 14, 16) in a building, characterised by providing a second layer structure (40, 60), inside the space covering at least a first layer structure (70, 16/80); defining continuous air gap (50), separated from the space between the first and the second layer structures providing an air inlet (30) at a lower level in the space (24) and communicating with the air gap (50); providing an air outlet (94) at a higher level in the space (24) and communicating with the air gap (50); and providing a heating source in the shape of a heating cable inside a portion of the air gap (50) parallel to a wall portion (16) of said portions the air gap (50) for providing an airflow in the air gap between the inlet (30) and the outlet (94) and capable of dehumidifying the layer structures. 